Transport system and transport method

ABSTRACT

A transport system comprises 2 apparatuses. The first transport apparatus notifies, for each of first physical ports, to the second transport apparatus, a valid first lane count and identification information of the first physical port. The second transport apparatus is configured to: obtain, for each of second physical ports, a valid second lane count and identification information of the second physical port; associate, based on the valid second lane count and the identification information of the second physical port, and the valid first lane count and the identification information of the first physical port, the identification information of the first and second physical port; and transmit, when data including identification information of one of the first physical ports is transmitted, the data from the second physical port that is identified by the identification information associated with the identification information of the one of the first physical ports.

CLAIM OF PRIORITY

The present application claims priority from Japanese patent applicationJP 2013-198574 filed on Sep. 25, 2013, the content of which is herebyincorporated by reference into this application.

BACKGROUND OF THE INVENTION

This invention relates to transport of signals of different protocols.

With the increase in communication traffic, networks are being demandedto be faster and larger in capacity. Large-capacity transport owing todata multiplexing has come to be used in backbone communication networksthat connect line concentrators, bases, or providers' networks to eachother. Examples of this large-capacity transport include SynchronousDigital Hierarchy/Synchronous Optical Network (SDH/SONET) in whichlow-rate signals are multiplexed into a signal of a predetermined rateto be transported as the signal, and Optical Transport Network (OTN)which accomplishes large-capacity transport by employing the concept ofan optical path that is suitable for wavelength division multiplexing(WDM).

A problem of the large-capacity transport network technologies describedabove is that accommodating a plurality of signals makes the apparatusconfiguration large. In this situation, for example, in JP 2003-143097A, there is disclosed a technology in which the detection ofsynchronization among a plurality of frame rates in SDH or SONET isaccomplished with a single circuit. In JP 2008-227995 A, there isdisclosed a multi-rate interface board in which low-rate signals thatare not standardized by OTN frame standards are turned into an OTN frameirrespective of the signal type.

In recent years, the diversification of signals (protocols) coupled to anetwork, which reflects their different uses, has also been observed.The link layer, for instance, has a mixture of various protocols such asthe Ethernet (trademark), Fibre Channel, and InfiniBand.

Against this background, there is an increasing demand in the field ofnetworks where links having different transport data rates aremultiplexed before transmitted for a signal multiplexing technologycompatible with multiple rates which does not depend on a specificprotocol or a specific transport data rate.

The technology disclosed in JP 2003-143097 A detects, on the premisethat transported signals are in the formats of SDH and SONET which arenetworks using synchronization protocols that heavily rely on accurateand stable clocks, multiple rates by detecting synchronization detectionpatterns unique to the respective formats. This technology thereforecannot detect signals of, for example, the Ethernet which runs onasynchronous clocks.

While transport in the OTN format allows for mapping irrespective of thesignal type, as well as integrated monitoring control of the overallnetwork, implementing the technology requires putting in a plurality oftransport apparatus in order to cover each OTN frame type standardizedby the ITU in advance.

The technology disclosed in JP 2008-227995 A detects multiple rates withthe use of an optical module code which is identification informationindicating the type of an optical module. This technology is thereforenot applicable to apparatus in which an optical module is not installed.

SUMMARY OF THE INVENTION

This invention relates to a data transport system and a data transportapparatus that have a plurality of physical ports including ones formulti-lane transport, that are capable of multiplexing data andtransporting the multiplexed data, and that are required to transportdata in a network where various link-layer protocols are used mixedly,and an object of this invention is to provide, in particular, asmall-sized data transport apparatus with little delay which is capableof multiplexing and demultiplexing data without depending on a specificlink-layer protocol or a specific transport lane count.

An aspect of the invention disclosed in this application is a transportsystem, comprising: a first transport apparatus for transporting datareceived by a plurality of first physical ports; and a second transportapparatus for receiving the data transported from the first transportapparatus and transmitting the received data from a plurality of secondphysical ports, wherein the first transport apparatus notifies, for eachof the plurality of first physical ports, to the second transportapparatus, a valid first lane count indicating how many of a pluralityof first lanes owned by the first physical port are valid, andidentification information of the first physical port that owns thevalid first lanes, and wherein the second transport apparatus isconfigured to: obtain, for each of the plurality of second physicalports, a valid second lane count indicating how many of a plurality ofsecond lanes owned by the second physical port are valid, andidentification information of the second physical port that owns thevalid second lanes; associate, based on the valid second lane count andthe identification information of the second physical port, and thevalid first lane count and the identification information of the firstphysical port which are notified by the first transport apparatus, theidentification information of the first physical port and theidentification information of the second physical port; and transmit,when data including identification information of one of the pluralityof first physical ports is transmitted from the first transportapparatus, the data from the second physical port that is identified bythe identification information associated with the identificationinformation of the one of the plurality of first physical ports which isincluded in the data.

According to the exemplary embodiment of this invention, data transportcan be made efficient. Other objects, configurations, and effects thanthose described above become apparent from the following description ofan embodiment of this invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an explanatory diagram illustrating Configuration Example 1 ofa transport system.

FIG. 2 is a block diagram illustrating the internal configurations ofthe transmitting apparatus and the receiving apparatus in the transportsystem of FIG. 1.

FIG. 3 is an explanatory diagram illustrating Configuration Example 2 ofthe transport system.

FIG. 4 is a block diagram illustrating the internal configurations ofthe communication apparatus 3-1 and 3-2 in the transport system of FIG.3.

FIG. 5 is an explanatory diagram illustrating an example of an alignmentmarker that is inserted in data transported in the transport system.

FIG. 6 is a sequence diagram illustrating a transport example in thetransport system.

FIG. 7 is an explanatory diagram illustrating Update Example 1 ofassociation tables.

FIG. 8 is another explanatory diagram illustrating Update Example 1 ofassociation tables.

FIG. 9 is Flow Chart 1 illustrating an example of a data transportprocessing procedure in one of the transport apparatus.

FIG. 10 is a flow chart illustrating an example of a data transportprocessing procedure in one of the transport apparatus that is a master.

FIG. 11 is a flow chart illustrating an example of a data transportprocessing procedure in one of the transport apparatus that is a slave.

FIG. 12 is explanatory diagram 1 illustrating transport example in thetransport system in which the multiplexer is installed in thetransmitting-side transport apparatus and the demultiplexer is installedin the receiving-side transport apparatus.

FIG. 13 is explanatory diagram 2 illustrating transport example in thetransport system in which the multiplexer is installed in thetransmitting-side transport apparatus and the demultiplexer is installedin the receiving-side transport apparatus.

FIG. 14 is explanatory diagram 3 illustrating transport example in thetransport system in which the multiplexer is installed in thetransmitting-side transport apparatus and the demultiplexer is installedin the receiving-side transport apparatus.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of an embodiment of this invention is dividedinto a plurality of embodiments or a plurality of sections if necessaryfor convenience. However, unless explicitly noted otherwise, theembodiments or sections are not irrelevant to one another, and one isrelated to another as a modification example, detailed or supplementarydescription, or the like of a part of or the entirety of the other. Whenthe count of pieces of a component or the like (including the count,numerical value, amount, and range of a component) is mentioned in thefollowing description of an embodiment of this invention, this inventionis not limited to the particular count mentioned and the component countcan be higher or lower than the particular count, unless explicitlynoted otherwise or unless it is theoretically obvious that the componentcount is limited to the particular count.

In the following description of an embodiment of this invention, acomponent (including a constituent step) is not always indispensableunless explicitly noted otherwise or unless it is theoretically obviousthat the component is indispensable. Similarly, when the shapes,positional relations, and the like of components are mentioned in thefollowing description of an embodiment of this invention, shapes and thelike that are substantially approximate to or similar to the onesmentioned are included unless explicitly noted otherwise or unless it istheoretically obvious that it is not the case. The same applies to thenumerical value and the range in the preceding paragraph.

In the following description of an embodiment of this invention,“transport lane” is a collective term for physical lanes, virtual lanes,Physical Coding Sublayer (PCS) lanes, and the like, and is not limitedto physical transport paths.

A transport system, receiving apparatus, transmitting apparatus, andcommunication apparatus according to an embodiment of this invention inone example have a plurality of physical ports and transport data in anetwork where various link-layer protocols are used mixedly.

The communication apparatus is an apparatus that has both a transmissionfunction of a transmitting apparatus for transmitting data and areception function of a receiving apparatus for receiving data. Atransport system is a system that includes one of a configuration fortransporting data from a transmitting apparatus to a receivingapparatus, a configuration for transporting data from a transmittingapparatus to a communication apparatus, a configuration for transportingdata from a communication apparatus to a receiving apparatus, and aconfiguration for transporting data from one communication apparatus toanother communication apparatus. A transmitting apparatus and acommunication apparatus may be configured so as to multiplex data andtransmit the multiplexed data. A receiving apparatus and a communicationapparatus may be configured so as to demultiplex multiplexed data. Thecollective term herein for a transmitting apparatus, a receivingapparatus, and a communication apparatus is “transport apparatus”.

An embodiment of this invention is described in detail below withreference to the drawings. The same components are denoted by the samereference symbols throughout all drawings that illustrate theembodiment, and repetitive descriptions thereof are omitted.

<Configuration Example of a Transport System>

FIG. 1 is an explanatory diagram illustrating Configuration Example 1 ofa transport system. The transport system of FIG. 1, which is denoted by100, includes a transmitting apparatus 1 and a receiving apparatus 2,and data is transported from the transmitting apparatus 1 to thereceiving apparatus 2. The transmitting apparatus 1 and the receivingapparatus 2 are connected to each other via a transport path which isconstructed of m transport lanes. A port number and a valid lane countmay be notified with the use of a path that is provided separately, ormay be notified with the use of the m transport lanes. The variable mindicates the total lane count of the transport path, and represents aninteger equal to or larger than 1. The valid lane count is the count oflanes along which valid data is transported.

FIG. 2 is a block diagram illustrating the internal configurations ofthe transmitting apparatus and the receiving apparatus in the transportsystem 100 of FIG. 1. The transmitting apparatus 1 includes n detectionunits 10 (10-1 to 10-n), a management unit 20, n insertion units 30(30-1 to 30-n), and a multiplexer 40. The variable n indicates the countof physical ports and represents an integer equal to or larger than 1.

The n detection units 10 (10-1 to 10-n) are connected to physical portsP1 to Pn, respectively. The physical ports P1 to Pn each accommodatetransport lanes. For example, the physical port P1 accommodates atransport lanes TxP1_(—)1 to TxP1_a, and the physical port Pnaccommodates x transport lanes TxPn_(—)1 to TxPn_x. The variables a andx are each an integer equal to or larger than 1.

The n detection units 10 (10-1 to 10-n) each detect the port number of aphysical port connected to a transport line and which transport lane ofthis physical port is valid. A valid lane is a transport lane at whichvalid data arrives from a transport line when the transport line isconnected to one of the physical ports P1 to Pn. The n detection units10 (10-1 to 10-n) respectively transport bit strings of data transportedalong valid lanes to their associated insertion units 30 (30-1 to 30-n).The detection units 10 may perform the detection when the transmittingapparatus 1 is powered on or when a physical port is connected.

The management unit 20 in the transmitting apparatus 1 receives portnumbers and valid lane counts from the n detection units 10 (10-1 to10-n) and transmits the received numbers and counts to their associatedinsertion units 30 (30-1 to 30-n). The management unit 20 in thetransmitting apparatus 1 also notifies a port number to the multiplexer40.

The n insertion units 30 (30-1 to 30-n) each insert a port number and avalid lane count from the management unit 20 into data that has beentransported from its associated detection unit. The n insertion units 30(30-1 to 30-n) each transport a bit string of the data in which the portnumber is inserted to the multiplexer 40.

The multiplexer 40 uses a port number notified from the management unit20 as a selection signal, and receives and multiplexes data transportedfrom the n insertion units 30 (30-1 to 30-n). The multiplexer 40transmits the multiplexed data to the transport path constructed of mtransport lanes.

The receiving apparatus 2 includes a demultiplexer 50, n analysis units60 (60-1 to 60-n), n reproduction units 70 (70-1 to 70-n), and themanagement unit 20.

The demultiplexer 50 demultiplexes multiplexed data from thetransmitting apparatus 1. The demultiplexer 50 transports a bit stringof the demultiplexed data to an analysis unit that is associated with aport number included in the data.

The n analysis units 60 (60-1 to 60-n) each take a port number out ofdata from the demultiplexer 50 and notifies the port number to themanagement unit 20 of the receiving apparatus 2. The n analysis units 60(60-1 to 60-n) each also transport a bit string of the data from thedemultiplexer 50 to its associated reproduction unit 70.

The n reproduction units 70 (70-1 to 70-n) are connected to physicalports P1′ to Pn′, respectively. The physical ports P1′ to Pn′ eachaccommodate transport lanes. For example, the physical port P1′accommodates a transport lanes RxP1_(—)1 to RxP1_a similarly to thephysical port P1, and the physical port Pn′ accommodates x transportlanes RxPn_(—)1 to RxPn_x similarly to the physical port Pn.

The management unit 20 of the receiving apparatus 2 notifies, along withvalid lane counts, port numbers that have been notified from the nanalysis units 60 (60-1 to 60-n) to their associated reproduction units70.

The n reproduction units 70 (70-1 to 70-n) are each notified of a portnumber and a valid lane count by the management unit 20 of the receivingapparatus 2, and allocate a bit string of data transmitted from itsassociated analysis unit 60 to a transport lane of the physical portconnected to a transport line in order to transport the bit string alongthe transport lane.

The management unit 20 of the receiving apparatus 2 counts, as a validlane, for each of the physical ports P1′ to Pn′, a transport lane of thephysical port along which a bit string of data is transported, andnotifies valid lane counts which are the counts of the thus countedvalid lanes and port numbers notified from the n analysis units 60 (60-1to 60-n) to the management unit 20 of the transmitting apparatus 1.

FIG. 3 is an explanatory diagram illustrating Configuration Example 2 ofthe transport system 100. The transport system 100 of FIG. 3 includestwo communication apparatus, and data is transported from one of thecommunication apparatus that is denoted by 3-1 to the othercommunication apparatus denoted by 3-2. The communication apparatus 3-1and the communication apparatus 3-2 each include the transmittingapparatus 1 and receiving apparatus 2 of FIG. 1. The transmittingapparatus 1 and the receiving apparatus 2 in each of the communicationapparatus 3-1 and 3-2 share a management unit. The transmittingapparatus 1 in the communication apparatus 3-1 is connected to thereceiving apparatus 2 in the communication apparatus 3-2, and thetransmitting apparatus 1 in the communication apparatus 3-2 is connectedto the receiving apparatus 2 in the communication apparatus 3-1.

FIG. 4 is a block diagram illustrating the internal configurations ofthe communication apparatus 3-1 and 3-2 in the transport system 100 ofFIG. 3. The relation between the transmitting apparatus 1 in thecommunication apparatus 3-1 and the receiving apparatus 2 in thecommunication apparatus 3-2 is the same as in FIG. 2. The relationbetween the transmitting apparatus 1 in the communication apparatus 3-1and the receiving apparatus 2 in the communication apparatus 3-2, too,is the same as in FIG. 2.

<Data Structure Example>

FIG. 5 is an explanatory diagram illustrating an example of an alignmentmarker that is inserted in data transported in the transport system 100.The alignment marker of 100G Ethernet is used here. The alignment markerincludes a header, a marker M0, a marker M1, a marker M2, bit parityBIP3, a marker M4, a marker M5, a marker M6, and bit parity BIP7.Information to be transported is also included.

The marker M0 is information that links a port number of a physical portto a local transmission/remote dealing identifier. A “local” means itsown apparatus, and a “remote” is a transport apparatus at the other endof the transport. For instance, to the transmitting apparatus 1 of FIG.1, the transmitting apparatus 1 is a local and the receiving apparatus 2is a remote. Similarly, to the receiving apparatus 2, the receivingapparatus 2 is a local and the transmitting apparatus 1 is a remote. Thelocal transmission/remote dealing identifier of data is an identifierfor identifying whether the data is “local transmission” or “remotedealing”. A local transmission identifier is an identifier that isassigned in the case where a local transports a port number detected bythe local to a remote. A remote dealing identifier is an identifier thatis assigned in the case where a local updates a port number transportedfrom the local and returns the updated port number to a remote.

The marker M1 is information that links the valid lane count of aphysical port whose port number has been detected by a local to amaster/slave identifier. A master/slave identifier is an identifier foridentifying whether its own apparatus is a master or a slave. Whetherits own apparatus is a master or a slave is set in advance. Themaster/slave identifier is referred to when there is a conflict betweenphysical ports.

The marker M2 is information that links the physical port number of aremote to an update OK/NG identifier. An update OK/NG identifier is anidentifier for identifying whether or not a port number and a valid lanecount have been established in a local, and “update OK” is assigned inthe case where a port number and a valid lane count have beenestablished, whereas “update NG” is assigned in the case where a portnumber and a valid lane count have not been established.

The bit parity BIP3 is the bit parity value of data. The marker M4 is avalue obtained by the bit-wise inversion of the marker M0. The marker M5is a value obtained by the bit-wise inversion of the marker M1. Themarker M6 is a value obtained by the bit-wise inversion of the markerM2. The bit parity BIP7 is a value obtained by the bit-wise inversion ofthe bit parity BIP3.

<Date Transport Sequence>

FIG. 6 is a sequence diagram illustrating a transport example in thetransport system 100. In the description of FIG. 6, the transportapparatus on the left is the master and the transport apparatus on theright is the slave. Pairs of a port number and a valid lane count arereferred to as “association table” in FIG. 6, and the management unit 20in one transport apparatus and the management unit 20 in the othertransport apparatus notifies their association tables to each other.

In FIG. 6, “communication unit” is a collective term for transmittingunits and receiving units. A “transmitting unit” includes the pluralityof insertion units 30-1 to 30-n and the multiplexer 40 which areillustrated in FIGS. 2 and 4. In the case where the multiplexer 40 isunnecessary, a “transmitting unit” equals the plurality of insertionunits 30-1 to 30-n. Similarly, a “receiving unit” includes the pluralityof analysis units 60-1 to 60-n and the demultiplexer 50 which areillustrated in FIGS. 2 and 4. In the case where the demultiplexer 50 isunnecessary, a “receiving unit” equals the plurality of n analysis units60-1 to 60-n.

The master detects a port number and a valid lane count through one ofthe detection units 10 (Step S601), and notifies the detected portnumber and valid lane count to the management unit 20 (Step S602). Themaster uses the management unit 20 to check resources of a physical portin question and to create an association table A, which includes thedetected port number and valid lane count (Step S603). In this step, themaster uses the relevant insertion unit 30 to set the local transmissionidentifier in the marker M0, set the master identifier in the marker M1,and set the update NG identifier which is a default value in the markerM2 in the association table A. The master then uses the communicationunit to transmit the association table A to the slave (Step S604).

Similarly, the slave detects a port number and a valid lane countthrough one of the detection units 10 (Step S611), and notifies thedetected port number and valid lane count to the management unit 20(Step S612). The slave uses the management unit 20 to check resources ofa physical port in question and to create an association table B, whichincludes the detected port number and valid lane count (Step S613. Inthis step, the slave uses the relevant insertion unit 30 to set thelocal transmission identifier in the marker M0, the slave identifier inthe marker M1, and set the update NG identifier which is a default valuein the marker M2 in the association table B. The slave then uses thecommunication unit to transmit the association table B to the master(Step S614).

The slave compares the association table B with the association table Atransmitted from the master, and updates the association table B (StepS615). The local transmission identifier is set in the association tableA transmitted from the master, and is used in the slave for an update ofthe association table B. In the updated association table B, the markerM0 is changed to the remote dealing identifier. The slave uses themanagement unit 20 to notify the updated association table B to themaster (Step S616).

The master receives the association table B transmitted in Step S614 andthe updated association table B notified in Step S616. The master doesnot use the association table B transmitted in Step S614 which has thelocal transmission identifier set therein for comparison with theassociation table A. The master compares the association table A withthe updated association table B notified in Step S614 which has theremote dealing identifier set therein, to thereby update the associationtable A (Step S605).

In the case where the association table A is established by the update,the master changes the marker M2 to “update OK” and transmits data fromthe communication unit to the remote (Step S606). The slave receives thedata, thereby linking up for data reception (Step S607). This completesthe sequence.

<Association Table Update Example>

FIG. 7 is an explanatory diagram illustrating Update Example 1 ofassociation tables. The description given here refers to the sequence ofFIG. 6. The master creates the association table A (Step S603), andtransmits the association table A to the slave (Step S604). The localtransmission/remote dealing identifier set in the created table is“local transmission”. The association table A here has port numbers P1to P3 and valid lane counts 20, 16, and 2 of the ports.

The slave creates the association table B (Step S613), and transmits theassociation table B to the master (Step S614). The localtransmission/remote dealing identifier set in the created table is“local transmission”. The association table B here has port numbers P1′to P4′ and valid lane counts 2, 16, 20, and 20 of the ports.

The master receives the association table B in Step S614 but does notcompare the association table B, in which the local transmissionidentifier is set, with the association table A. This is because theassociation table B has not been updated in the slave based on theassociation table A, and there is accordingly a chance of conflict,which is described later.

The slave compares the association table A and the association table Bin Step S615, and updates the association table B. In the comparisonbetween the association tables A and B, port numbers that have the samevalid lane count are associated with each other. Accordingly, in theassociation table A, the port number P1 is associated with the portnumbers P3′ and P4′, the port number P2 is associated with the portnumber P2′, and the port number P3 is associated with the port numberP1′. In the association table B, the port number P1′ is associated withthe port number P3, the port number P2′ is associated with the portnumber P2, the port number P3′ is associated with the port number P1,and the port number P4′ is associated with the port number P1.

In the association table A, where the port number P1 is associated withthe port numbers P3′ and P4′, one port is associated with a plurality ofports, thereby creating a conflict. In order to solve the conflict, theslave updates the association table B by deleting an entry for the portnumber P4′ from the association table B. The slave notifies the updatedassociation table B to the master (Step S616).

Receiving the updated association table B notified in Step S616, themaster compares the updated association table B with the associationtable A and updates the association table A (Step S605). In thecomparison between the association tables A and B, port numbers thathave the same valid lane count are associated with each other as in thedescription given above. Accordingly, in the association table A, theport number P1 is associated with the port number P3′, the port numberP2 is associated with the port number P2′, and the port number P3 isassociated with the port number P1′. This establishes the associationtable A of the master, which means that the master is ready for datatransport to the slave.

FIG. 8 is another explanatory diagram illustrating Update Example 1 ofassociation tables. The difference from FIG. 7 is that, opposite to FIG.7 where the transport apparatus on the left is the master and thetransport apparatus on the right is the slave, the master in FIG. 8 isthe transport apparatus on the right, with the transport apparatus onthe left serving as the slave. The association tables A and B in FIG. 8are the same as the ones in FIG. 7.

The master creates the association table B (Step S603), and transmitsthe association table B to the slave (Step S604). The localtransmission/remote dealing identifier set in the created table is“local transmission”. The association table B here has port numbers P1′to P4′ and valid lane counts 2, 16, 20, and 20 of the ports.

The slave creates the association table A (Step S613), and transmits theassociation table A to the master (Step S614). The localtransmission/remote dealing identifier set in the created table is“local transmission”. The association table A here has port numbers P1to P3 and valid lane counts 20, 16, and 2 of the ports.

The master receives the association table A in Step S614 but does notcompare the association table A, in which the local transmissionidentifier is set, with the association table B.

The slave compares the association table A and the association table Bin Step S615, and updates the association table A. In the comparisonbetween the association tables A and B, port numbers that have the samevalid lane count are associated with each other. Accordingly, in theassociation table A, the port number P1 is associated with the portnumbers P3′ and P4′, the port number P2 is associated with the portnumber P2′, and the port number P3 is associated with the port numberP1′. In the association table B, the port number P1′ is associated withthe port number P3, the port number P2′ is associated with the portnumber P2, the port number P3′ is associated with the port number P1,and the port number P4′ is associated with the port number P1.

In the association table A, where the port number P1 is associated withthe port numbers P3′ and P4′, one port is associated with a plurality ofports, thereby creating a conflict. In order to solve the conflict, theslave updates the association table A by deleting an entry for the portnumber P1 from the association table A. The slave notifies the updatedassociation table A to the master (Step S616).

Receiving the updated association table A notified in Step S616, themaster compares the updated association table A with the associationtable B and updates the association table B (Step S605). In thecomparison between the association tables A and B, port numbers thathave the same valid lane count are associated with each other as in thedescription given above. Accordingly, in the association table B, theport number P1′ is associated with the port number P3 and the portnumber P2′ is associated with the port number P2. Port numbers that areassociated with the port numbers P3′ and P4′ are not in the associationtable A, and the master therefore deletes entries for the port numbersP3′ and P4′ from the association table B. This establishes theassociation table B of the master, which means that the master is readyfor data transport to the slave.

<Examples of a Data Transport Processing Procedure>

Examples of a data transport processing procedure in the transportsystem 100 are described next with reference to FIGS. 9 to 11. A flowchart of FIG. 9 is an example of a processing procedure that is executedregularly or when an execution instruction is received, irrespective ofwhether the own apparatus is a master or a slave. A flow chart of FIG.10 is an example of a processing procedure that is executed when the ownapparatus is a master. A flow chart of FIG. 11 is an example of aprocessing procedure that is executed when the own apparatus is a slave.

FIG. 9 is Flow Chart illustrating an example of a data transportprocessing procedure in one of the transport apparatus. The transportapparatus waits for the insertion of a communication module, which isconnected to a transport line, into a physical port (Step S901: No) and,when a communication module is inserted (Step S901: Yes), detects a portnumber and a valid lane count through the relevant detecting unit 10(Step S902).

The transport apparatus next determines whether or not a firstassociation table is found in storage of its own apparatus (Step S903)and, when the first association table is found (Step S903: Yes), movesto Step S905. When the first association table is not found (Step S903:No), the transport apparatus uses the information detected in Step S902to create the first association table (Step S904), and then moves toStep S905. The first association table is an association table that iscreated by its own apparatus. Accordingly, in the case of FIG. 7, thefirst association table is the association table A when the transportapparatus that is executing the processing procedure is the master, andthe first association table is the association table B when thetransport apparatus that is executing the processing procedure is theslave. The transport apparatus then transmits the first associationtable to the other transport apparatus which is the remote (Step S905).

FIG. 10 is a flow chart illustrating an example of a data transportprocessing procedure in one of the transport apparatus that is a master.The master transport apparatus first determines whether or not there arethe first association table and a second association table (Step S1001).The second association table is an association table that is notifiedfrom the other transport apparatus which is the remote (the slave, inthis case). For example, in the case of the master of FIG. 7, the mastercreates the association table A which is the first association table,and receives the association table B which is the second associationtable created and notified by the slave.

When there are the first association table and the second associationtable (Step S1001: Yes), the master determines whether or not the secondassociation table has the local transmission identifier (Step S1002).When the second association table has the local transmission identifier(Step S1002: Yes), this second association table cannot be used in acomparison with the first association table, and the master thereforereturns to Step S1001. When the second association table has the remotedealing identifier (Step S1002: No), on the other hand, the master movesto Step S1003.

In the example of FIG. 7, the association table B (the secondassociation table) notified by the slave in Step S614 has the localtransmission identifier set in the marker M0, and therefore is notcompared with the association table A (the first association table).

The master next determines whether or not the association between thefirst association table and the second association table is consistent(Step S1003). In other words, the master determines whether or notphysical ports of the master and physical ports of the slave can beassociated with each other on a one-to-one basis when the valid lanecount is the same in a master physical port and a slave physical port(Step S1003). The master moves to Step S1006 when the association isconsistent (Step S1003: Yes), and to Step S1004 when the association isnot consistent (Step S1003: No). For example, the comparison in StepS605 of FIG. 7 reveals that the association table A and the associationtable B are consistent with each other.

When the association is not consistent (Step S1003: No), the masterdetermines whether or not there is a conflict between ports (StepS1004). When there is a conflict between ports (Step S1004: Yes), themaster moves to Step S1006. When there is no conflict between ports(Step S1004: No), on the other hand, the master updates the firstassociation table as illustrated in Step S605 of FIGS. 7 and 8 (StepS1005). In the example of FIG. 7, the master writes port numbers of theslave in a column for an associated physical port (corresponding to themarker M2 of FIG. 5) in the association table A.

Thereafter, the master again determines whether or not the associationbetween the first association table and the second association table isconsistent (Step S1006). The master modifies the first association tableautomatically or through a user's operation (Step S1007) when theassociation is not consistent (Step S1006: No). In the case of automaticmodification, the master deletes the last entry in the first associationtable, for example. The master transmits the modified first associationtable to the slave (Step S1009). After the modification, the firstassociation table is written over in the storage inside the master.

When it is determined in Step S1006 that the association is consistent(Step S1006: Yes), on the other hand, the master establishes portnumbers and valid lane counts in the first association table (StepS1009). This enables the master to transport data to the slave with theuse of a valid lane of an established physical port.

FIG. 11 is a flow chart illustrating an example of a data transportprocessing procedure in one of the transport apparatus that is a slave.The slave transport apparatus first determines whether or not there arethe first association table and a second association table (Step S1101).The second association table is an association table that is notifiedfrom the other transport apparatus which is the remote (the master, inthis case). For example, in the case of the slave of FIG. 7, the slavecreates the association table B which is the first association table,and receives the association table A which is the second associationtable created and notified by the master.

When there are the first association table and the second associationtable (Step S1101: Yes), the slave determines whether or not theassociation between the first association table and the secondassociation table is consistent (Step S1102). In other words, the slavedetermines whether or not physical ports of the slave and physical portsof the master can be associated with each other on a one-to-one basiswhen the valid lane count is the same in a master physical port and aslave physical port. The slave moves to Step S1104 when the associationis consistent (Step S1102: Yes), and to Step S1103 when the associationis not consistent (Step S1102: No). For example, the comparison in StepS615 of FIG. 7 reveals that the association table A and the associationtable B are not consistent with each other, and that there is also aconflict.

When the association is not consistent (Step S1102: No), the slaveupdates the first association table as illustrated in Step S615 of FIGS.7 and 8 (Step S1103). In the case where there is a conflict, too, theslave solves the conflict through Step S1103. Then, the remote dealingidentifier is set in the marker M0 of data in the first associationtable.

Thereafter, the slave notifies the first association table to the master(Step S1104). The notification corresponds to Step S616 of FIGS. 6 to 8.

<Application Examples of the Multiplexer and the Demultiplexer>

FIGS. 12 to 14 are explanatory diagrams illustrating transport examplesin the transport system 100 in which the multiplexer 40 is installed inthe transmitting-side transport apparatus and the demultiplexer 50 isinstalled in the receiving-side transport apparatus. The transportapparatus of this embodiment are capable of transporting data on aport-by-port basis and, with the multiplexer 40 and the demultiplexer 50provided in the transport system 100, the order of data multiplexing anddata demultiplexing can therefore be changed on a port-by-port basis. Inaddition, which port is to be used for multiplexing or demultiplexingcan be selected, and paths can therefore be selected flexibly in amanner suited to multiple rates.

FIG. 12 illustrates an example of the operation of the multiplexer 40and the demultiplexer 50 which are included in the transport system 100.In this operation, when the multiplexer 40 has a ratio of 58:40, forexample, the transmitting-side transport apparatus multiplexes inputdata of fifty-eight lanes in order from the physical port P1 to thephysical port P4, and outputs the multiplexed data as data of fortylanes. The demultiplexer 50 that has a ratio of 40:58 demultiplexesinput data of forty lanes in order from P1 to P4, and outputs thedemultiplexed data as data of fifth-eight lanes.

In FIG. 13, physical port-by-physical port basis control is madepossible with the use of a port number-valid lane count associationtable provided by the management unit 20. The order of multiplexinginput data of fifty-eight lanes and the demultiplexing order cantherefore be changed, as well as physical ports of the local andphysical ports of the remote.

For instance, the transmitting-side transport apparatus multiplexes dataof the physical ports P1, P3, P2, and P4 in the order stated, followinga port number-valid lane count association table which is provided bythe management unit 20, and outputs the multiplexed data as data offorty lanes. The 40:58 demultiplexer follows association tableinformation, which is included in a marker inserted in the data, indemultiplexing the input data of forty lanes in order of P1, P3, P2, andP4. The association table information further allows the demultiplexerto change transmitting-side physical ports and physical ports of theremote so that data of the physical port P1 of the local is changed todata of the physical port P3′ of the remote, while data of P2 is changedto data of P2′, data of P3 is changed to data of P4′, and data of P4 ischanged to data of P1′. The demultiplexer outputs the changed data asdata of fifth-eight lanes.

FIG. 14 illustrates an operation of multiplexing data of the physicalports P1 and P3 preferentially. For example, the multiplexer 40multiplexes data of only the physical ports P1 and P3 and outputs themultiplexed data as data of forty lanes. The 40:58 demultiplexer followsassociation table information, which is included in a marker inserted inthe data, in demultiplexing the input data of forty lanes. Theassociation table information further allows the demultiplexer to changephysical ports of the transmitting-side transport apparatus and physicalports of the receiving-side transport apparatus so that data of thephysical port P1 (P3) of the local apparatus is changed to data of thephysical port P3′ (P4′) of the receiving-side transport apparatus. Thedemultiplexer outputs the changed data as data of fifth-eight lanes.

Specifically, the user sets a priority level for each physical port inthe transport apparatus, for example. The user may set priority so that,for example, transmission data from a high-speed physical port having ahigh transport rate is multiplexed/demultiplexed preferentially. Inaddition, the transport apparatus can be implemented by a singlecircuit, which enables the transport apparatus to have a small size, todeal with the user's requests flexibly, and to transport large-capacitydata through multiple ports.

The transport system 100 according to this embodiment has a plurality ofphysical ports including ones for multi-lane transport, is capable ofmultiplexing data and transporting the multiplexed data, and is usefulin a network where various link-layer protocols are used mixedly. Inparticular, the transport system 100 is capable of multiplexing anddemultiplexing transmission data from a plurality of physical ports ofdifferent protocols or transport lane count, without depending on aspecific link-layer protocol or a specific transport lane count. Inaddition, each transport apparatus of this embodiment can be implementedby a single circuit, and a small-sized transport apparatus with littledelay that is capable of multi-rate transport of large-capacity data isthus accomplished.

This invention has been described in detail so far with reference to theaccompanying drawings, but this invention is not limited to thosespecific configurations described above, and includes various changesand equivalent components within the gist of the scope of claimsappended.

What is claimed is:
 1. A transport system, comprising: a first transportapparatus for transporting data received by a plurality of firstphysical ports; and a second transport apparatus for receiving the datatransported from the first transport apparatus and transmitting thereceived data from a plurality of second physical ports, wherein thefirst transport apparatus notifies, for each of the plurality of firstphysical ports, to the second transport apparatus, a valid first lanecount indicating how many of a plurality of first lanes owned by thefirst physical port are valid, and identification information of thefirst physical port that owns the valid first lanes, and wherein thesecond transport apparatus is configured to: obtain, for each of theplurality of second physical ports, a valid second lane count indicatinghow many of a plurality of second lanes owned by the second physicalport are valid, and identification information of the second physicalport that owns the valid second lanes; associate, based on the validsecond lane count and the identification information of the secondphysical port, and the valid first lane count and the identificationinformation of the first physical port which are notified by the firsttransport apparatus, the identification information of the firstphysical port and the identification information of the second physicalport; and transmit, when data including identification information ofone of the plurality of first physical ports is transmitted from thefirst transport apparatus, the data from the second physical port thatis identified by the identification information associated with theidentification information of the one of the plurality of first physicalports which is included in the data.
 2. The transport system accordingto claim 1, wherein the second transport apparatus associates theidentification information of the first physical port and theidentification information of the second physical port when the validfirst lane count and the valid second lane count match.
 3. The transportsystem according to claim 1, wherein, when the identificationinformation of the first physical port is associated with pieces ofidentification information of two or more second physical ports out ofthe plurality of second physical ports, the second transport apparatusassociates so that identification information of only one secondphysical port out of the plurality of second physical ports isassociated with the identification information of the first physicalport.
 4. The transport system according to claim 1, wherein the firsttransport apparatus comprises a multiplexer for multiplexing the datareceived by the plurality of first physical ports, and wherein thesecond transport apparatus comprises a demultiplexer for demultiplexingthe multiplexed data from the first transport apparatus, uses thedemultiplexer to demultiplex the multiplexed data, and transmits thedemultiplexed data from the second physical port that is identified bythe identification information associated with the identificationinformation of the first physical port.
 5. The transport systemaccording to claim 4, wherein the first transport apparatus is capableof setting one of the plurality of first physical ports as a specificfirst physical port which has priority over other of the plurality offirst physical ports, and the multiplexer multiplexes data received bythe specific first physical port out of the plurality of first physicalports to transmit the multiplexed data to the second transportapparatus.
 6. The transport system according to claim 1, wherein, whenthe first transport apparatus is set as a master and the secondtransport apparatus is set as a slave, the second transport apparatusnotifies, to the first transport apparatus, information indicating anassociation relation between the identification information of the firstphysical port and the identification information of the second physicalport, and wherein, based on the information indicating the associationrelation, the first transport apparatus associates the identificationinformation of the first physical port and the identificationinformation of the second physical port, and, after finishingassociating the identification information, transmits pieces of datarespectively received by the plurality of first physical ports to thesecond transport apparatus.
 7. The transport system according to claim6, wherein, when the valid second lane count and the identificationinformation of the second physical port that owns the valid second lanesare obtained, the second transport apparatus notifies the valid secondlane count, the identification information of the second physical port,and information that is not to be updated to the first transportapparatus, and wherein, when receiving the valid second lane count, theidentification information of the second physical port, and theinformation that is not to be updated which are notified by the secondtransport apparatus, the first transport apparatus avoids associatingthe identification information of the first physical port with theidentification information of the second physical port.
 8. A transportmethod performed in a transport system, the transport system comprising:a first transport apparatus for transporting data received by aplurality of first physical ports; and a second transport apparatus forreceiving the data transported from the first transport apparatus andtransmitting the received data from a plurality of second physicalports, the method comprising: notifying, by the first transportapparatus, for each of the plurality of first physical ports, to thesecond transport apparatus, a valid first lane count indicating how manyof a plurality of first lanes owned by the first physical port arevalid, and identification information of the first physical port thatowns the valid first lanes; obtaining, by the second transportapparatus, for each of the plurality of second physical ports, a validsecond lane count indicating how many of a plurality of second lanesowned by the second physical port are valid, and identificationinformation of the second physical port that owns the valid secondlanes; associating, by the second transport apparatus, based on thevalid second lane count and the identification information of the secondphysical port, and the valid first lane count and the identificationinformation of the first physical port which are notified by the firsttransport apparatus, the identification information of the firstphysical port and the identification information of the second physicalport; and transmitting, by the second transport apparatus, when dataincluding identification information of one of the plurality of firstphysical ports is transmitted from the first transport apparatus, thedata from the second physical port that is identified by theidentification information associated with the identificationinformation of the one of the plurality of first physical ports which isincluded in the data.